The cell culture, cell characterization and cytokine core will play a central role in the Program project "Growth Control of Multiple Myeloma". This facility will facilitate all other projects by providing tumor banking and tissue triaging services. In addition they will provide basic data to the Myeloma Data Bank by phenotyping all patients' myeloma cells and measuring the expression of a variety of cytokines in myeloma cells and patients' sera. These assays will be accomplished by flow cytometry, immunocytochemistry and in situ hybridization. In addition, the laboratory will measure expression of a number of biological molecules which may be significant in myeloma including multiple drug resistance, glucocorticoid receptor, GSH, Ki67, as well as proliferative activity. this core will provide important data on factors involved in control of myeloma cells and how these molecules change during the clinical course of the disease. In addition, it will provide biological specimens which are well characterized for all other projects.